This study by the University of Florida, Jacksonville, reviewed 25 patients (≤21 years old) with nonmetastatic Ewing sarcoma of the cranium and skull base treated with PBT. This study reported that with the median follow-up of 3.7 years, the 4-year local control, disease-free survival, and overall survival rates were 96%, 86%, and 92%, respectively, with no patient lost. Two patients experienced in-field recurrences. One patient experienced bilateral conductive hearing loss requiring aids, two patients developed intracranial vasculopathy, and 6 patients required hormone replacement therapy for neuroendocrine deficits.

None developed a secondary malignancy. This study concludes that PBT is associated with a favorable therapeutic ratio in children with large Ewing tumors of the cranium and skull base with excellent local control and no marginal recurrences, however treatment dosimetry predicts limited long-term neurocognitive and neuroendocrine side effects.